EZGO Marathon Duromax 16

carguymn

Well I bit the bullet, got tired of the the weak Robin 295 and ordered a 16 hp Duromax from Maxtool and 1" shaft clutch from CPP. Pulled the engine/swingarm from cart last night. Looks like making an engine mount plate shouldn't be too difficult.

I do have a couple of questions that I hope someone can help me with.....

1 - has anyone swapped in one of these clones and have pics of how they mounted it?

2 - any pics of pulse line hook up?

3 - I have heard that the charging circuit on these engines is pretty weak, has anyone mounted a GM style 1 wire alternator to these?

Any help will be appreciated.

I will take pics and post what I come up with.

BGW

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AirJunky

Right on. Good luck & take loads of pics for us.

I haven't done the mod myself, but have considered it. Should be interesting to watch.

sho305

I posted pics of a G9 yamaha install here
http://www.buggiesgonewild.com/gas-y...cs-thread.html

Bought a spacer from AGK (affordablegokart.com) for $15 or whatever it was, replaces the one behind the carb and has a nipple for your fuel pump. You can make your own if you have a piece of tube to epoxy into it, TheNewGuy did that find his thread of a G1 yamaha he turned into a jeep its really cool, I think in yamaha gas section. Charging is 3A or some stupid thing, you can add another one under the flywheel I guess but it looks much more involved to make it charge more the rectifier is different there is a voltage regualtor iirc, you can use honda parts. We kept the stock generator so it charges too and no problems running lights and such just like before. Used a CPP adapter on the crank, in the yamaha had to cut the crank way back so the adapter sits against the shoulder just to fit the engine in there and still had to cut the airbox back. It came loose last weekend I told him we needed a nut inside it, cart went lean was missing like crazy. Pushed it back tight and it was fine.

You might want to consider a cam for it, Precision Cam says they have a mild cam that gives 1K more rpm and it can use it. It would not go faster than stock 28gps on gravel drive, now it seems to go a little faster that its broken in...but not like a V twin. I will be putting a cam in mine unless they are really expensive, and advancing the timing. It has great bottom end though.

carguymn

Thanks for the suggestions. Low end power is what I'm after. Where it will be used is some steep pasture land and the kids will be on it too, so high speed is not a priority. I plan on leaving the governot in it for now also.

sho305

It seems to have a lot of bottom end, very similar to stock except double or more the power. I think it could pull the front if clutched enough, but would not be nice to drive around that way. Even with the stock clutch it has a lot of power just does not jump to it like more clutch would. It starts just like stock too.

AirJunky

Talk to Tom at CPP about improving the stock clutch on the rear diff. The spring upgrade, replacing the ramps, and I guess they can resurface them too.

I doubt the clutch on the engine will be useable with the bigger engine. But he may be able to tell you more there too.

sho305

Most people take their power kits out of the clutch when they big block, but I don't know. This cart I put 16hp in, I put new sheave on the stock yami clutch it had holes in it, and put cut sheave on the stock secondary spring. The other sides of the clutches are steel and don't wear, so they are essentially new.

The yamaha clutch will work fine, you just can't do much with it far as tuning. I don't know about other brand clutches like ezgo. I will be messing with the clutches on mine when I put the 16hp in it, though I already have worked them over years ago. Want to put a spring in it, it works well moving just takeoff could get a boost.

KENNETHC

sho 305 i was wondering about the stock yamaha clutch. someone hear said they dont beleive it would work. they engage immediatly and probably would not idle and want to take off as soon as it started. i have my duromax 16 in garage waiting on funds for clutch from ccp. i cant stand it not being in my yamaha. i just want more torque and top end is what it is. i also am a little nervous about cutting the shaft off for adapter to work.

carguymn

Engine and clutch came today. I hope to get to working on it later this week and weekend.

sho305

It works about exactly like it does with the stock engine, since we used the stock generator/starter because we like that and the clone does not charge the battery much...so we don't have the problem of shifting while running. I can shift with the engine still turning under idle speed, but yes that will be a problem if you have it run all the time. You will have to figure out how to spring the clutch, or put a brake pad on the secondary to stop it, etc. I wondered about an old door lock solenoid actuator hooked to a brake pad against the secondary, then use a microswitch just like the reverse buzzer on the yamaha, to activate it in neutral, or put a momentary switch at/on the shifter you could hit.

Far as running, it runs similar rpm to the stock engine not sure exactly of any difference without a tach but sounds the same. The 16 clone has a healthy bottom end it has significantly more power than stock, I'd guess the torque is easily over double. It is down on power a little the first cartlength like the stocker is due to lower rpm, but with a load it revs more just like stock (on a hill or with trailer, etc). It has enough power that stopped on a steep hill of grass, it takes off pretty good with two full size men on it. This was a steep ditch over 6' high, my stock cart feels like it can't get over it with two people, crawls with one, the clone 16 lofted the front tires and spun the rears over the top. It was tall grass next to the road. Dang I have to get some video of it. We stop with the front tires on the bottom of it then go so it has no chance to get going.

We were testing it last weekend and I jetted the carb again, think it is spot on now. Anyway before the airbox got a leak it was running great, it only takes about 2 seconds to hit full running rpm when you floor it from not running and still. It pulls up to high rpm faster than the stock engine because it has more power. At part throttle it kind of eases away like stock. I'd say with a different clutch it would launch harder the first few feet. You should be able to fit a cart replacement clutch from comet or that style if you cut the crank and use the stock one now because they have the same taper, if you can still buy them. I cut the crank to 1 1/8" long x 1" dia, and sanded the edge a little so its a hair under that long.

If you are doing a G9/G2 look closely at my yamaha clone thread the pics, the air cleaner at carb fit is a pain. We may end up making a box to fit on the carb. I'd rather put a turned intake behind the carb so the carb aims out the rear if I can but his I'd have to redo all the linkages to it then. Not found a manifold like that yet, they do make them for 6.5hp. I could make one I guess. On that the original part of the air cleaner we made a cover to fit inside it where the filter goes and sealed it, put the 1 1/4" pipe fitting into the side of it. The actual air filter is ahead of the clutch. We will get rid of that deal eventually I might have found a rubber boot with a 90 degree turn we can put on there on the carb, for a 20hp onan.